You can view the molecule on the reference screen located in the top right corner of the game screen.

5.2.

How do I move a game piece (atom)?

To move a game piece (atom) use your mouse cursor to click on it. At this time the available directional icon will become visible. Click on the corresponding directional icon to make a game piece move into the desired direction. Alternatively, you can use your keyboard to move the pieces. Use the Tab key to switch between the items, and the cursor keys to move them once selected.

5.3.

Can I use the keyboard to control the pieces (atoms)?

Yes. Use Tab key to switch between the items, and he cursor keys to move them once selected.

5.4.

When I move a piece (atom) it goes right past the place where I want it. How do I make it stop there?

You don't. Once an atom begins moving, it will not stop until it meets either a wall or another piece.

5.5.

I cannot beat the level. Is there a hint system, or a solver?

No. Unfortunately at this time KAtomic does not feature a hint system. So the only way to finish a level is to solve it on your own.